1. Field of the Invention
The present invention relates to a curing apparatus which dries the paste on workpieces in which chips are bonded to lead flames by the paste.
2. Prior Art
Examples of conventional curing apparatuses include the curing apparatuses described in Japanese Utility Model Application Publication (Kokoku) No. 6-19546, Japanese Patent Application Laid-Open (Kokai) Nos. 4-5838 and 5-109792, etc.
In these curing apparatuses, a plurality of prismatic heating blocks which heat the workpieces are installed at equal intervals along the conveying direction of the workpieces. Japanese Utility Model Application Publication (Kokoku) No. 6-19546 further discloses the respective heating blocks heated in stages from the workpiece entry point toward the workpiece exit point; accordingly, the temperatures of the respective heating blocks are independently controlled. For example, if eight heating blocks are employed, the first three heating blocks (counting from the workpiece entry side) are controlled to a temperature of 250.degree. C., the next two heating blocks are controlled to a temperature of 270.degree. C., and the remaining three heating blocks are controlled to a temperature of 250.degree. C.
In the prior art described above, a plurality of heating blocks are merely installed at equal intervals, and no consideration is given to the fact that adjacent heating blocks affect each other in terms of heat. As a result, temperature control of the respective heating blocks is difficult, and reliable temperature control is impossible.